MPPa-PDT suppresses breast tumor migration/invasion through inhibiting AKT-NF-κB-dependent MMP-9 expressions via ROS
Abstract Background: breast cancer is the most commonly women cancer and most breast cancer deaths are related to tumor metastasis. Therefore, inhibiting metastasis may provide a therapeutic treatment for breast cancer. In the present study, pyropheophorbide-α methyl ester mediated photodynamic therapy (MPPa-PDT) was used to inhibit metastasis in breast cancer cells MCF-7. Methods: Uptake of MPPa was detected by fluorescence microscope. Cell viability was evaluated by CCK-8. Generation of ROS were detected by DCFH-DA. Migration of cells was assessed by wound healing assay and invasion ability was assessed by Matrigel invasion assay. Levels of MMP2 and MMP9 were measured by PCR. Akt, Phospho-Akt, Phospho-NF-kB p65 and NF-kB p65 were measured by western blotting. F-actin cytoskeleton was observed by immunofluorescence. Lung organs were stained with Hematoxylin and Eosin. Results: Following MPPa-PDT, migration and invasion were decreased in the MCF-7 cells. MPPa-PDT down-regulated expression of MMP2 and MMP9 which is responsible for metastasis. MPPa-PDT reduced the phosphorylation of AKT and NF-κB. MPPa-PDT also destroyed cytoskeleton F-actin in MCF-7 cells. These effects were blocked by the reactive oxygen scavenger NAC or AKT activator SC79 while PI3K inhibitor LY294002 or AKT inhibitor Triciribine increased these effects. Moreover, MPPa-PDT inhibited tumor metastasis and destroyed F-actin in vivo. Conclusion: taken together, these results demonstrated that MPPa-PDT inhibits metastasis of MCF-7 cells both in vitro and vivo, and that may involve in AKT-NF-κB-dependent MMP-9 signaling pathway. Thus, MPPa-PDT may be a promising therapeutic treatment to inhibit metastasis.